An implantable flexible fiber generator without encapsulation made from differentially oxidized carbon nanotube fibers

Abstract

Stable and sustainable energy supply for wearable and implanted electronics is essential for the long-term and safe living body application. A biocompatible flexible wearable and implanted energy supply without encapsulation is urgently needed to meet the demand of body comfortability and safety. Here we report a flexible, lightweight and biocompatible fiber power generator which repeatedly produces electricity in various fluids. The generator is made from two aligned carbon nanotube (CNT) fibers by modifying them with different oxygen-containing groups. The system sustains more than 150 discharge/recovering cycles without obvious decay in specific capacitance of 8.0 F/m2 (4.5 F/g, 2.5 × 106F/m3) in deionized water. The recovered electricity generation is attributed to the control of the surface coverage of reactants on aligned CNTs when immersed into water during the conversion process from chemical energy to electricity. Its generality, easy fabrication and light weight are demonstrated to be promising for various applications that are highly desired while remain challenging currently, e.g., in a mouse body to stimulate the nerve without encapsulation of the device.